Hydraulic device



July 26, 14938. R. :SYKORA 2,124,300

"HYDRAULIC DEVICE Filed Jan. 4, 1938 2 Sheets-Sheet l In venior:

July 26, 193s.- YK gR-A 2,124,800

HYDRAULIC DEVICE Filed Jan. 4, 1938 2 Sheets-Sheet 2 flitor/zeys.

Patented July 26, 1938 PATENT OFFICE areasoc 1 HYDBAUHC DEVICE RudolfSyhora, Boston, Mass, assignor of onehalf to Q. Wesley Hale,Springfield, Mass.

Application January 4, 1938, Sei-ial No. 183,299 8 Claims. (Ci. 103-457)This invention relates to hydraulic devices and more particularly tocertain improvements in the hydraulic device disclosed in my priorPatent No. 1,430,602, dated October 3, 1922.

It is the primary aim and object of the present invention to simplifythe construction of the above patented device and to increase theefliciency thereof.

Before explaining in detail the present invention it is to be understoodthat the invention is not limited in its application to the details ofconstruction and arrangement of parts illustrated in the accompanyingdrawings, since theinvention is capable of other embodiments and ofbeing practiced or carried out in various ways. Also it'is to beunderstood that the phraseology or terminology employed herein is forthe purpose of description andnot of limitation, and it is not intendedto limit the invention claimed herein beyond the requirements of the.prior art.

In the drawings:

Fig. 1 is a side elevation of a rotary device which embodies the presentinvention.

Fig. 2 is a plan view of the device, partly fragmentary.

Fig. 3 is a section taken substantially on the line 3-3 of Fig. 6.

Fig. 4 is a longitudinal section through the easing of the device.

Fig. 5 is a longitudinal section through certain detail structure of thedevice.

Figs. 6, 7 and 8 are.cross-sections taken substantially on the lines6-6, I1 and 88, respectively, of Fig. 1.

Referring to the drawings, the reference numeral i0 designates apreferably cast casing (Fig. 4) which is cylindrically bored at H toreceive sleeve portions i2 and I3 (Fig. 5). The sleeve portions l2v andI3 define a cylinder chamber It (Fig. 3) which is closed at both ends byend covers l5, securedin any suitable manner to the casing l0.Journalled in suitable bearings it, provided by the end covers I5, is ashaft ll which 'is provided with a transverse rib or wing l8 that 45 isof the same thickness as the diameter of the shaft I'I. Moreparticularly, the end faces l9 of the wing I8 slidably engage theadjacent machined surfaces 20 of the end covers l5, while the curvedside faces l9a of said wing slidably engage the cylindrical wall 2| ofthe cylinder chamber ll (Figs. 3 and 8). Hence, the wing l8 divides thecylinder chamber I 4 into two equal piston chambers 22 and 23, each ofwhich is substantially semi-circular in cross-section (Figs. 6 and 7).Moreover, the wing l8 effectively seals the able, simple manner.

piston chambers 22 and 23 against leakage of fluid from one chamber tothe other chamber.

Longitudinally slidable in the piston chambers 22 and 23 are identicalpistons 24 and 25, respectively. These pistons 24 and 25 are preferablyof the light weight skeleton type illustrated in Figs. 2 and 6 to 8inclusive, and are provided with a stud 25 and an anti-friction roller27. The rollers 21 project into a continuous cam groove 28 which isformed by the spaced machined end surfaces 29 and 30 (Fig. 5) of thesleeve portions 82 and i3, respectively, and the cylindrical inner wallit of the casing it. The cam groove 28 is of such design that thepistons 25 and 25 are reciprocated in their chambers 22 and 23 in opp0'site directions on rotation of the shaft ii and its wing it. The shafti'i may be driven from any suitable prime mover (not shown).

In the above mentioned Patent No. 1,430,602, the cam groove 28 has beendirectly machined into the cylindrical inner wall H of the casing 90.

This proved tobe a most difiicult operation which was totally unsuitedfor production purposes. The casing had to be chucked at one end so asto admit a machining tool through the other end. The working portion ofthe tool had to extend a considerable distance from its support, causingundesirable vibrations in the same which effected the quality of themachining operation. Resetting of the tool after sharpening proved to bemost diflicuit and required considerable skill, particularly since theinternal cam groove was more or less hidden from the operators vision.For the same reason, the machining operation was beyond visualinspection by the operator. In 3 contradistinction to the aboveoperation, the present invention provides for cutting the cam grooveinto a sleeve from the outside thereof until the entire wall thicknesshas been penetrated by the tool, leaving the sleeve portions i2 and I3(Fig. '5). This is a simple and rapid operation which does not requirevery much skill. Moreover, the operator may easily follow the progressof the tool into the sleeve and readily reset the tool after sharpeningthe same. The chucking of the sleeve is also greatly facilitated, thesame being merely placed over a driven arbor and drivingly connectedwith the same in any suit- The tool moves longitudinally of the sleevewhile the latter rotates, and is gradually worked into the sleeve untilit is finally parted. The sleeve portions i2 and I; are then insertedinto the cylindrical bore II of the casing II) from opposite endsthereof and secured therein in any suitable manner when their respectiveend surfaces 3|, 32 and 33, 34 (Figs. 4 and 5) are flush. The width ofthe cam groove 23 is-then equal to the one previously machined into thesleeve, because the length of the latter was equal to that of the casingl0. Care has to be taken that the sleeve portions l2 and i3 reassumetheir proper angular relative positions in the casing in order that thecam groove 28 is of equal width throughout. This, however, offers nodifllculty, and may be greatly facilitated by appropriately marking theend surfaces .32, 34 and 3|, 33 of the casing and the sleeve,respectively before the latter is parted.

As best shown in Fig. 2, the cam groove 28 lies in a plane whichintersects the center of the interior of the casing I0 and is inclinedwith respect to a vertical plane A-A through the axis of the casing ,asshown in plan view in Fig. 2. The cam groove 28 is, therefore, in formof an ellipse, with the result that the pistons are moved longitudinallyin opposite directions at uniform speed on rotation of the shaft i1 atuniform speed. The rise of the cam groove 28, i. e. the distance B inFig. '2, is moreover substantially equal to the length of the cylinderchamber 14 (Fig. 3) less the length of one of the pistons, so that thepistons are moved from one end of said cylinder chamber to the other endthereof, and vice versa.

While in the above mentioned Patent No.

. 1,430,602'the fluid had to pass through two degree bends when enteringthe casing and also when leaving the same, thereby meeting withconsiderable resistance, the present invention contemplates a leastobstructed flow of fluid into .and from the casing. To this end, thecasing I0 sleeve portions i 2, i 3, respectively (Figs. 3 to '1) and theend covers l5 (Fig. 3). More particularly, all the radial ports 39 and40, 4| and 42, 43 and 44, and 45, 46 are located in a plane which passesthrough the" axis of shaft l1 and is parallel thereto as appears bestfrom Figs. 3.

6 and 7.

The passage 31 has centrally thereof an outlet 41, assuming thereby'that the shaft and the pistons are rotated in the direction of thearrow 48 in Figs. 2, 3 and 6. The passage 33 has centrally thereof aninlet 43.

The cam groove 28 is soccrrelated with theports 39 and 46, 4| and 42, 43and 44, '45 and 46 that the pistons 24, 25 assume the end positionsshown in Fig.2, when the wing ll assumes the dot-and-dash line positionIla in Fig. 6. On rotating the'wing from the dot-and-dash line positionIn in the direction of the arrow 43 (Figs. 2 and- 6) and if the presentdevice is used as a pump, the piston 24 is moved/to the right as viewedin Figs. 2 or 3', thereby drawing fluid from the inlet 43 into thegradually increasing chamber portion 22a (Fig. 3) by way of the spiralpassage 36 and the radial ports 43, 44 (Fig. 6), and simultaneouslyforcing fluid through the outlet 41 from the gradually decreasingchamber portion 22b 8. 3) by-way of the radial ports 42, 4i and the p mpassage 31 (Fig. 7). The piston 24 will arrive in its right endposition, corresponding to that of piston 25 in Fig. 2,after one-halfrevolution of the wing l8. On continued rotation of the wing IS, the camgroove 28 will move the piston 24 to the left as viewed in Fig. 2 andreturn said piston into the illustrated left end position at the end ofthe next semi-revolution of said wing. During this return movement ofthe pisinto the gradually increasing chamber portion 22b by way of thespiral passage 38 and the radial ports 45, 46 (Fig. 7) which are then incommunication with said chamber portion 22b, and simultaneously forcesfluid from the gradually decreasing chamber portion 22a and through theoutlet 41 by way of the spiral passage 31 and the radial ports 40, 39(Fig. 6) which are then in communication with said chamber portion 22a.

The piston 25 is reciprocated in exactly the same manner as, andsimultaneously with, the piston 24. However, the pistons 24, 25 movealways in opposite directions due to their angular displacement ofdegrees from each other and with respect to the cam groove 28. Hence,both "pistons are double-acting and continuously force fluid of the samequantities 'per time unit through the outlet 41, and draw fluid of thesame quantities per time unit through the inlet 49 and into theirrespective piston chambers. More particularly, the pistons 24, 25continuously and simultaneously force fluid from the opposite ends ofthe cylinder chamber l4 through the two opposite branches of the spiralpassage 31 and through the centrally located outlet 41, whereby saidpistons alternately force fluid through each of said branches duringeach revolution of the shaft i 1. Conversely, the pistons 24, 25continuously and simultaneously draw fluid from the inlet through thetwo opposite branches of the spiral passage 33 and into the oppositeends of the cylinder chamber l4, whereby said pistons alternately drawfluid through each of said branches and into each end of said cylinderchamber during each revolution of the shaft i1.

In order to prevent the two separate streams of fluid, which arecontinuously discharged from the opposite branches of the spiral passage31 into the outlet 41, from clashing against each other and thus addappreciably to the other minor losses of the pump, such as loss of headdue to friction, a guide fln 50 is preferably cast in the outlet 41which extends transversely to the directions of flow of said streams anddiverts the same into substantial parallelism when entering the outlet.Likewise, a guide fin 5| in the inlet 49 gradually diverts the fluidinto the opposite branches of the spiral passage 38.

end, the casing ill is provided with a lubricantcontaining reservoir 55which is broken through at 56 (Fig. 8) to communicate with thecylindrical bore ll of said casing. More particularly,

the. reservoir is located centrally of thelength of the casing in. andin alignment with the nearest portion of the cam groove 23 (Fig.- 3) sothat the lubricant level in said reservoir may extend into said camgroove. An elbow 52 is ton 24, the same draws fluid from the inlet 43threaded into the reservoir 55 and closed by a plug 59. Refilling of thereservoir with lubricant merely requires removal of the plug 59. As therollers 21 pass the reservoir 55 and are slightly d pped into .thelubricant therein, a small quantity of lubricant is carried by saidrollers through the entire cam groove 28, thereby continuouslylubricating the same. Some of the lubricant will also seep through thefine clearances between the pistons 24 and 25, the wing l8 and thecylindrical wall M of the sleeve portions l2 and i3, and even into thebearings I6, thereby also inbricating the reciprocating pistons 24, 25and the rotating shaft l1, and effectively sealing the piston chambers22 and 23 against leakage of fluid from one to the other. The lubricantfilm on the walls of the piston chambers and on the pistons themselvesserves also to protect said chambers and pistons against corrosion byo'ertain fluids, be it liquid or gas, for which the device may be used.

The present lubricator is noteworthy for its simplicity, it merelyrequiring the reservoir 55 but no special structure for conducting theinbricant from said reservoir to the places of application. The rollersTl, which have already a definite function, namely, to causereciprocation of the pistons, additionally function as lubricantconveyors.

In view of the foregoing description, the present device has among itsmain advantages a very simple casing which may be readily cast with thespiral passages 37 and 38 and the inlet and outlet 49, 61. These spiralpassages 31 and 3B assure a least obstructed flow of the fluid throughthe pump. Low frictional resistance to' the fluid in the device is,therefore, an important advantage of the present device.

The provision of the spiral passages 31 and 38 in the casing iiirestricts the flow of fluid through the device within the confines ofthe casing, with the result that the end covers 65 can be made of a verysimple construction without any fluid-com ducting passages.

The provision of the fluid-diverting fins 50 and in the outlet d1 andinlet 39, respectively, further improve the efficiency of the presentde* vice.

The provision of the cam-groove forming sleeve portions l2 and I3 notonly permits replacement of these sleeve portions in the casing, butgreatchambers.

bearings for the shaft I! be dispensed with, but

and, due to its efficient operation, adds to the life of the device.

By making the thickness of the wing 48 equal to the width of the ports40, 44 and 46, 42 of the sleeve portions l2 and 4-3, respectively, thewing l8 will in only one of its angular positions closeall of saidports, i. e., when the wing assumes the dot-and-dash line position l8ain Fig. 6. By reversing the pistons just when the wing assumes themomentary angular position IBa, assurance is given that fluid has alwaysaccess'to the drawing ends of the pistons and may always be displacedfrom the cylinder chambers when compelled by the piston ends.

-Due to the equal longitudinal'travel of the pistons in oppositedirections, no thrust is imparted to the wing l8 regardless of theinternal hydraulic pressure and partial vacuum in the piston Hence, notonly can expensive thrust of the cylinder through ports of uniform theend faces IQ of the wing I8 do not wear on the adjacent cover surfaces20 and induce leakage of fluid therebetween.

While the present device has been described as v a pump in the foregoingdescription, it is to be distinctly understood that the same can also beadvantageously used. as a fluid motor, wherein fluid under pressure isthe driving power and cam groove in its annular wall, and a reservoir incommunication with said cam groove and containing lubricant whichextends into said cam groove; and a piston in said cylinder having afollower cooperating with. said cam groove for reciprocating said pistonon rotation of the same,

said follower dipping into the lubricant on rotation of the piston,thereby lubricating the cam groove and the cylinder wall.

2. In a device of the type described, the combination of means providinga cylinder having a continuous'camgroove in its annular wall, and areservoir in communication with said cam groove and containing lubricantwhich extends into said .cam groove; means for forming a rotary chamberin said cylinder; and a piston in said chamber having a follower incooperation with said cam groove for reciprocating said piston on beingrotated with its chamber, said follower dipping into the lubricant oneach rotation of the piston thereby lubricating the cam groove and saidchamber.

3. In a'device of the type described, the combination of means providinga cylinder having a continuous cam groove in its annular wall, and areservoir in communication with said cam groove and containing lubricantwhich extends into said cam groove; means for forming separate rotarychambers in said cylinder; and pistons in said chambers having followerscooperating with said cam groove for reciprocating said pistons on beingrotated with their chambers, said followers dippinginto the lubricant oneach rotation of the pistons thereby lubricating the cam groove and thechambers and sealing the latter against leakage of fluid from one to theothr.

4. In a device of the type described, the combination of a memberproviding a cylinder and inlet and outlet ports of uniform width in theannular cylinder wall at both ends thereof; a diametrically disposedpartition member in the cylinder forming two separate chambers thereinand being adjacent said annular wall of a uniform thickness equal to thewidth of said ports, one of said members being rotatable about thecylinder axis and said ports being so disposed that they are closed bythe partition member in one angular position only of the rotatablemember; a double-acting piston in each chamber; and means reciprocatingsaid pistons in opposite directions passage surrounding a peripheralhalf of the cylinder and communicating with the opposite ends? in theannular wall thereof ;'a diametrically disposed partition member in thecylinder forming two separate chambers therein and being adjacent saidannular wall of a uniform thickness equal to the width of said ports,one of said members being rotatable about the cylinder axis and saidports being so disposed that they are closed by the partition member inone angular position only of the rotatable member; a double actingpiston in each chamber and means reciprocating said pistons in oppositedirections on rotation of the rotatable member.

6. The combination set forth in claim 5, wherein the two spiral passagesare provided centrally thereof with an inlet and outlet, respectively.

7. The combination set forth in claim 5, wherein thetwo spiral passagesare provided centrally thereof with an inlet duct and outlet duct,respectively, and a fluid-diverting fin in at least one of saidpassages, said fln extending across said one passage in a plane whichintersects the central duct thereof.

8. In a device of the type described, the combination of means providinga cylinder and an inlet and outlet port in the annular cylinder wall ateach end thereof, all 01 said ports lying in a plane parallel to andextending through the cylinder axis; a plane partition of uniformthickness in the cylinder, said partition being rotatable about thecylinder axis for forming two separate rotary chambers in said cylinder,the width of the ports being equal to the thickness of the partition sothat the latter closes said ports in only one of its angular positions;a double acting piston in each chamber; and means reciprocating saidpistons in opposite directions on rotation of said partition.

' RUDOLF' SYKORA.

